Process of hulling rice.



PATBNTBD MAY a, 1904.v

lNo, 758,664.

' R. E. KIMBALL..

PROCESS OBHULLING mes. APPLICATION FILED KAB. 12, 1903. I0 IODEL.

z Nonms PtTERS 00. mo'rfxuwojwnsnmurou, n. c.

UNITED STATES Patented May 3, 1904.

PATENT OEEICE.

ROBERT E. KIMBALL, OF CLEVELAND, OHIO, ASSIGNOR OF TWO-THIRDS TO L. H.WEBB AND E. L. THURSTON, OF CLEVELAND, OHIO.

PROCESS OF HULLING RICE.

SPECIFICATION forming part of Letters Patent N0. 758,664, dated May 3,1904.

Application filed March 12, 1903. Serial No. 147,399. (No specimens.)

' To all whom it may concern.-

Be it known that I, ROBERT E. KIMBALL, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Processes of HullingRice, of which the following is a full, clear, and exact description,reference being had tothe accompanying drawings.

The removal of the husks or hulls from rice without breaking a largepercentage of the rice-kernels is a problem which has not heretoforebeen solved. This has been due, primarily, to the peculiar relativecharacteristics of the rice-kernel and its hull. The former is verybrittle, while the` hull is tough and elastic.

The greater part of the rice grown in the world is hulled to-day, as ithas been for ages, between millstones. This process is defective,because a large part of the rice is not hulled by one passage betweenthe stones and, further, because a large proportion of the kernels whichare hulled are broken.

In very recent times the use of machines has been begun for hullingrice, and some of these machines are eiiicient in a profitable degree,because they do slightly increase the percentage of rice which is hulledand they do slightly reduce the percentage of broken kernels.

The object 0f this invention is to rapidly hull a large proportion ofthe rice treated without any breakage worth considering. In practicingthe invention with an eiiicient apparatus a very large percentage of therice may be hulled by one operation, and the percentage of breakage willbe so small as to be practically negligible.

The invention is a process which consists,

generically, in imparting rapid motion to the hull-covered rice-kernelsand in then suddenly checking the forward movement of-v the hulls only,whereby the inertia of the inclosed kernels causes them to press onwardand burst the hull and escape therefrom. The necessary rapid motion Igive to the hull-covered rice by means of an air-blast impelling italong a channel of considerable length, so that the movement of the ricehas time to become greatly accelerated. This is also included within myinvention.

' Finally, the invention consists also in the process, when carried outmore specifically in accordance with the Jfollowing specifications,` asdefinitely set forth in theA claims.

In the practice of the process some apparatus is required, as is thecase in all processes in which air-blasts are employed, because it isnecessary to have ducts orconduits for efficiently guiding the air andrestraining it from dissipating its force in useless directions.

The drawings represent a simple apparatus capable of use in the practiceof the process. This apparatus is, however, only one formJ of apparatuswhich may be employed for the practice of this process.

Figure 1 of the drawings is a sectional side elevation of saidapparatus. Fig. 2 is a view thereof in the direction indicated by thearrow of Fig. 1, and Fig. 3 is a sectional view on line F G of Fig. l.

Referring to the parts by letters, a represents the smooth surface alongwhich the hullcovered rice is caused to slide by means of an air-blastcoming from the nozzle B, and a represents a frictional retardingsurface, which is of concave form and, though deflecting, is a practicalcontinuation of said smooth surface. In the apparatus shown these twosurfaces constitute the inner surface of the rear wall of a tube A, bymeans of which the air-blast is confined and properly guided,and at theupper end of this tube there is a hopper a3, through which thehull-covered rice is fed into this tube.

The apparatus is comparatively long to allow the rice to becomesuiciently accelerated under the force of the blast, an intermediateportion of the tube being broken out -in the drawings. The length of thetube and the force of the blast will vary greatly with the grade of therice and other circumstances; but I may say, just by way ofillustration, that I have successfully employed a tube one inch indiameter (at its cylindrical part) and fifteen feet long with anair-blast of about thirty pounds to the square inch. If one desires tohull the greatest percentage of the rice with the least percentage ofbreakage, it is necessary that the rice shall slide in a singlethickstream along this smooth surface, and by single-thick stream is meant astreamv whereof substantially every kernel slides upon this surface.This single thickness of the stream may be brought about by allowingonly a small quantity of rice to flow through the tube or by suicientlywidening the surface a and a to take care of all the rice which does iowor by arranging that wall of the tube that opposes the smooth surface soclose thereto that there remains between them only room enough for thepassage of one rice-kernel. Some expedient must also be adopted to causesaid rice to be projected against said smooth surface in such wise thatit will not be broken and will not rebound and will hold itself againstsaid surface as it goes forward. I prefer to secure these results bydirecting the air-blast against said smooth surface atavery acute angle,as indicated in Fig. l of the drawings, wherein the arrow D indicatesthe direction of the air-blast. When the rice carried by the air-blastmeets this surface, there is no danger of breakage or of any rebounding,and thereafter the inertia of the rice holds it against this surface asthe air-blast carries it along.

The concave frictional retarding -surface must be a practicalcontinuation of the smooth surface, so that the rice in passing from thesmooth surface onto this retarding surface does not sensibly change itsdirection of travel. The rice-hull as it passes onto thisretarding-surface is checked in its movement, and checked so suddenlythat the inclosed ricekernel by its own inertia forces its Way out ofthe hull, which it splits in so doing. This frictional retarding-surfacemay be made of carborundum, which is believed to be the best surface forthe purpose. It may, however, be made of stone, vulcanized rubber, oremery cloth or any other material having the necessary characteristics.This surface, however, must not have any projections high enough to getin front of the rice-kernel or any part thereof as it slides along overthe surface. If the rice did strike such a projection, the kernel wouldgenerally be broken, and, moreover, the forward movement of said kernelwould probably be checked thereby, so that it would not force its wayout of the hull. This surface should preferably be a concave surface ofincreasing curvature toward the discharge end. Thereby the liability ofthe rice to iy from the surface is lessened, because the inertia is moreeffective in holding it on such surface while the described action takesplace.

As heretofore stated, the apparatus shown is so constructed that theinertia of the rice holds the same against the smooth and frictionalsurfaces; but the desired result might be secured by locating the frontwall of tube so close to said surfaces that the rice would beconstrained to slide thereon.

Having described my invention, I claim- 1. The herein-described processof hulling rice, which consists in propelling the hullcovered rice, bymeans of an air-blast, in a single-thick stream, along a smooth surface,and thence onto a frictional retarding-surface, which is a practicalcontinuation of said smooth surface for the purpose set forth.

2. The herein-described process of hulling rice, which consists inpropelling the hullcovered rice, by means of an air-blast, in asingle-thick stream, along a smooth surface, which crosses the directionof the blast at a very acute angle, and thence onto a deliectingfrictional retarding-surface, which is a practical continuation of saidsmooth surface, for the purpose set forth.

3, The herein-described process of hulling rice, which consists inrapidly propelling the hull-covered rice, by means of an air-blast,along a smooth surface, and, thence, onto a deiecting frictionalretarding-surface, which is a practical continuation of said smoothsurface, for the purpose specified.

4. The herein-described process of hulling rice, which consists inimparting rapid movement to the hull-covered rice by means of anair-blast, and then suddenly checking the movement of the hull only,whereby the inertia of the inclosed kernel causes it to burst the hulland force its Way out of the same.

5. The herein-described process of hulling rice consisting of impellingthe hull-covered berry along a channel of sufcient length to permit itto acquire a high velocity, and suddenly checking the hull whereby theinertia of the inclosed kernel causes it to burst the hull and force itsway out of the same.

6. The herein-described process of hulling rice consisting inaccelerating the movement of the hull-covered berry until it hasattained a high velocity and then suddenly checking the hull, wherebythe inertia of the inclosed kernel causes it to burst the hull and forceits way out of the same.

7. The herein-described process of hulling rice which consists inimpelling the hull-covered rice at a rapid rate in a substantiallysingle-thick stream along a smooth surface IOO IIO

and thence ontoadeecting frictional retardwhich is a practicalcontinuation of said ing-surface. y smooth surface. IO

8. The herein-described process of hulling In testimony whereof Ihereunto aflx my rice which consists in. propelling thehull-covsignature in the presence of two Witnesses.

5 ered rice by means of an air-blast onto and ROBERT E. KIMBALL.

along a smooth surface which crosses the W'itnesses: direction of theblast at a very acute angle E. B. GILCHRIST, and thence onto africtional retarding-surface E. L. THURsToN.

